阅读理解。 (1) Russia is proud of its circus (马戏) performers . It has the oldest circus school in the world--Moscow Circus School. (2) Every year more than a thousand children from other countries want to enter this school. However, only about 70 of them are chosen. (3) less, the, old, be, must, eleven, students, years, than. They must be talented and good at sports as well. Students at the Moscow Circus School learn a lot. Besides the same basic (基础) subjects as those in other schools, they have to learn four circus subjects. Those subjects sound fun, but they are difficult to learn. For example, it can take years of practice for a student to walk on the high wire. While learning and practicing, the students always wear safety belts. (4) So if they ______ mistakes, they will not get hurt. After seven years of study, (5) the students are supposed to leave school . The graduates usually work in the circuses and can make a lot of money. 1. 请将 （1）处的句子改成同义句。 Russia ______ its circus performers. 2. 请将（2）处的句子翻译成汉语。 ________________________________________________ 3. 请将（3）处的单词组合成一个完整的句子。 ________________________________________________ 4. 在文中（4）处的空白处填上一个适当的单词，使句意完整。 So if they ______ mistakes, they will not get hurt. 5. 对（5）处的画线部分提问。 ________________________________________________?